A conventional bed mattress may have the following drawbacks in use:
1. After being used for a time period, some springs may lose their resilience due to elastic fatigue, which are difficult to be repaired as firmly secured inside the bed mattress. To discard the damaged mattress for instance, having only two or three springs damaged may be wasteful or may increase the problem of waste disposal of garbage. PA1 2. The transporting or handling a big conventional nonseparable bed such as a double bed, may be obstructed by a narrow door or window especially of a small apartment. PA1 3. During the making of a conventional bed mattress, each of the plural springs must be firmly secured inside the mattress by a conventional fixation method thereby increasing the production cost and maintenance difficulty.
The present inventor has found the drawbacks of a conventional bed mattress and invented the present assembled bed mattress with springs jacketed in sleeves.